2x^2+6x-31=0

解答

2 x^{2} + 6 x - 31 = 0

x = \frac{- 3 + 71}{2}, x = - \frac{3 + 71}{2}

十进制

x = 2.71307 \dots, x = - 5.71307 \dots

求解步骤

2 x^{2} + 6 x - 31 = 0

使用求根公式求解

x_{1, 2} = \frac{- 6 \pm 6 ^{2} - 4 \cdot 2 ( - 31 )}{2 \cdot 2}

6^{2} - 4 \cdot 2 (- 31) = 271

x_{1, 2} = \frac{- 6 \pm 2 71}{2 \cdot 2}

将解分隔开

x_{1} = \frac{- 6 + 2 71}{2 \cdot 2}, x_{2} = \frac{- 6 - 2 71}{2 \cdot 2}

x = \frac{- 6 + 2 71}{2 \cdot 2} : \frac{- 3 + 71}{2}

x = \frac{- 6 - 2 71}{2 \cdot 2} : - \frac{3 + 71}{2}

二次方程组的解是:

x = \frac{- 3 + 71}{2}, x = - \frac{3 + 71}{2}

32 = 704 + 16 t - 16 t^{2}

s im pl i f y (- 18 m^{2} n)^{2} (- \frac{1}{6} m n^{2})

s im pl i f y (\frac{64}{25})^{- \frac{1}{2}}

s im pl i f y \frac{9 ^{12}}{9 ^{8}}

\frac{( 3 x - 5 )}{2} + \frac{( 8 x - 12 )}{7} = 9